Project Description

This project introduces students to the idea of the “universe” – the totality of all stars and galaxies – then takes them through the evidence that the universe is expanding. The discovery of the expanding universe was one of the greatest revelations of 20th Century astronomy. Students will make a “Hubble diagram,” named for the astronomer who first made one, for galaxies from the SkyServer database.

This activity is well-suited for differentiation within a classroom setting as it allows students to work at their own pace as they interact with a variety of questions, exercises, and activities that increase their knowledge of astronomy, the scientific inquiry process, technology, and mathematics.


  • Scientists have evidence that the universe is expanding
  • The big bang is part of the evidence of the expanding universe
  • Data have been collected on the magnitude, brightness, distance, and spectrum for many galaxies in our universe
  • These data can be graphed and analyzed to understand the expansion of the universe

Target Audience

Students in grades 6 through 12 would benefit from the concepts and activities that are included in this project. Although the content is primarily related to astronomy, other scientific content areas can be taught using it, such as scientific inquiry, physics, motion, the electromagnetic spectrum, and using technology to make scientific discoveries.

Classroom Time

The project can be completed in five to six 45-minute class sessions.

The first lesson should include the first three “pages” of the student section- namely “The Universe: Your Cosmic Address”, “The Universe: How Big is It?”, and “The Expanding Universe”. The remainder of the lessons are self-paced, and should be completed by most students in four to five class sessions.

This project lends itself very nicely to differentiation in the classroom, as those students who are more capable can proceed at their own pace, and can complete an optional research project. The teacher is freed up to circulate around the class and offer individual and small group assistance as needed.

Real World Relevance

This project helps students gain an understanding of the vastness of our universe. It helps them to conceptualize how are universe began, and gives them perspective on its current rate of expansion. Finally, it allows them to see where our Earth fits into the universe.